title: Wernicke encephalopathy after bariatric surgery: a systematic review.
abstract: OBJECTIVE
  To review the clinical essentials of Wernicke encephalopathy (WE) after bariatric surgery.
  
  
  BACKGROUND
  An estimated 205,000 bariatric surgical procedures were performed in the United States in 2007. Such procedures may potentially lead to severe nutritional complications.
  
  
  METHODS
  Literature searches were performed in Medline, Embase, and abstract collections. Inclusion criteria were WE after bariatric surgery, diagnosed by the presence of two or more of the following signs: mental status changes, eye movement abnormalities, cerebellar dysfunction, and dietary deficiency.
  
  
  RESULTS
  Of 104 reported cases of WE after bariatric surgery, 84 cases were included. Gastric bypass or a restrictive procedure had been performed in 80 cases (95%). Admission to hospital for WE occurred within 6 months of surgery in 79 cases (94%). Frequent vomiting was a risk factor in 76 cases (90%) and had lasted for a median of 21 days at admission. Intravenous glucose administration without thiamine was a risk factor in 15 cases (18%). Brain magnetic resonance imaging identified lesions characteristic of WE in 14 of 30 cases (47%). Incomplete recovery was observed in 41 cases (49%); memory deficits and gait difficulties were frequent sequela. The recent increase in the use of bariatric surgery in the United States was associated with an increase in reported WE cases.
  
  
  CONCLUSIONS
  The number of WE cases after bariatric surgery is substantially higher than previously reported. Surgeons, allied health providers, and patients need to be aware of the predisposing factors and symptoms to prevent and optimize the management of this condition.
authors.affiliation: Department of Medicine, Aker University Hospital and Faculty Division Aker University Hospital, University of Oslo, Oslo, Norway. e.t.aasheim@medisin.uio.no
authors.forename: Erlend Tuseth
authors.initials: ET
authors.lastname: Aasheim
mesh_terms: D050110:Bariatric Surgery / Q000009:adverse effects*; D006801:Humans; D011183:Postoperative Complications / Q000453:epidemiology; D014839:Vomiting / Q000453:epidemiology; D014899:Wernicke Encephalopathy / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control